The scope of the present invention is that of munitions designed to be fired from artillery guns, and more specifically, those which are fired by means of a propellant charge which may or may not be separated from the actual projectile.
Presently, there is a tendency nowadays to increase gun calibers (i.e., the diameter of the barrel), and more particularly those of tank guns. Higher initial projectile speeds may thereby be obtained.
However, the diameter of the chamber is generally not increased in the same proportions so as to restrict the overall diameter of the weapon.
Weapon designers therefore find themselves forced to increase the length of the chamber in order to maintain an expansion ratio (total volume barrel+chamber/volume chamber) which enables the desired speed performances to be reached.
In such a context the problem of the overall size of the munitions arises. This problem is often solved by dividing the load into two load elements (one carrying the projectile and possibly some powder, and another of powder alone).
However, if it is possible, with such a division of the munition, to design projectile munitions of the arrowhead type (sub-caliber shafts, fin-stabilized) wherein the length of the load remains limited, it is not possible to define munitions with explosive projectiles without being forced to:
- either lengthen the projectile carrying load,
- or reinforce the mechanical resistance of the projectile, thereby reducing its stability and effectiveness.
In fact, the arrowhead shafts are able to penetrate to a relative depth into the powder without any problems of mechanical resistance.
The envelope of explosive munitions can not penetrate the explosive charge without it becoming essential to increase its thickness, which leads to a decrease in its stability and a reduction in the internal volume devoted to the explosive charge, thereby reducing its effectiveness.
The obturator which ensures gastightness must therefore be situated to the rear of the envelope of the explosive projectile, forcing the projectile carrying load to be lengthened.